Carboxy methyloxy succinates

ABSTRACT

There are disclosed herein detergent compositions containing a water-soluble organic detergent compound and as a builder therefor the normal alkali metal, ammonium or alkanol amine salts of ether polycarboxylic acids selected from the group consisting of oxydisuccinic acid, and carboxymethyloxysuccinic acid.

United States Patent [1 1 Lamberti et al.

[ Oct. 21, 1975 CARBOXY METHYLOXY SUCCINATES Inventors: Vincent Lamberti, Upper Saddle River; Mark D. Konort, Haworth, both of N.J.; Ira Weil, New York,

v N .Y.

Assignee: Lever Brothers Company, New

York, N.Y.

Filed: July 22, 1974 Appl. No.: 490,618

Related US. Application Data Continuation of Ser. No. 145,961, May 21, 1971, abandoned, which is a continuation-in-part of Ser. No. 80,166, Oct. 2, 1970, Pat. No. 3,692,685, which is a continuation-in-part of Ser. No. 879,627, Nov. 24, 1969, Pat. No. 3,635,830, which is a continuation-in-part of Ser. No. 731,700, May 24, 1968, abandoned.

US. Cl. 260/535 P; 252/82; 252/89; 252/DIG. 11; 252/132; 252/135; 252/539; 260/247.2 R; 260/429.9; 260/439 CY; 260/50l.1; 260/501.17

[51] Int. Cl. C07C 59/23 [58] Field of Search 260/535 P, 429.9, 439 R, 260/439 CY, 247.2 R, 501.1

References Cited OTHER PUBLICATIONS E. von Rudloff, et al., Canadian J. of Chemistry, Vol. 35, pp. 315-321, 1957.

Primary ExaminerJames A. Patten Assistant Examiner-P. J. Killos acid.

11 Claims, No Drawings CARBOXY METHYLOXY SUCCINATES This is a continuation, of application Ser. No. 145,961, filed May 21 1971, now abandoned which is a continuation'in part of application Ser. No. 80,166, filed Oct. 12, 1970, now U.S. Pat. No. 3,692,685 which in turn is a continuationinpart of application Ser. No. 879,627, filed Nov. 24, 1969, now U.S. Pat. No. 3,635,830 which in turn is a continuation-in-part of ap plication Ser. No. 731,700, filed May 24, 1968 and now abandoned.

The present invention relates to detergent compositions containing a novel builder therefor.

BACKGROUND Eutrophication is the process of excessive fertilization of aquatic plants through enrichment of waters with nutrients, such as carbon, nitrogen, phosphorus, potassium, iron, trace metals and vitamins. Factors in the eutrophication of lakes, streams and estuaries are natural runoff, agricultural drainage, groundwater, precipitation, sewage and waste effluents.

Although there is no present adequate proof, it has been postulated that the phosphorus-containing builders present in detergent compositions can be a factor in eutrophication. Therefore any substituted which do not contain phosphorus may decrease to some extent the eutrophication.

It is, therefore, an object of the present invention to provide detergent compositions with a builder compound which is free of phosphorus.

The compositions of the invention necessarily include both a synthetic builder and a water-soluble or ganic detergent compound. Such detergent compounds that are useful in the present invention are the anionic (soap and nonsoap), nonionic, zwitterionic and ampholytic compounds. The chemical nature of these detergent compounds is not an essential feature of the present invention. Moreover, such detergent compounds are well known to those skilled in the detergent art and the patent and printed literature are replete with disclosures of such compounds. Typical of such literature are Surface Active Agents by Schwartz and Perry and Surface Active Agents and Detergents by Schwartz, Perry and Berch, the disclosures of which are incorporated by reference herein.

The phosphorus-free builders for the detergent compositions of the invention are the normal alkali metal, ammonium and lower mono-, diand trialkanolamine salts of ether polycarboxylic acids selected from the group consisting of oxydisuccinic acid and carboxymethyloxysuccinic acid. The oxydisuccinic acid is also known as 2,2-oxydisuccinic acid.

The ether polycarboxylic acids and the builder salts thereof of the present invention can be generally represented as follows:

MOOC-C-H R MOOC H H COOM wherein R is H or CH COOM and M is selected from the group consisting of alkali metal, ammonium and substituted ammonium cations such as morpholinium,

alkyl-ammonium, mono-, diand trialkanol ammonium and H.

Typical of such materials are tetrasodium oxydisuccinate, tetrapotassium oxydisuccinate, tetralithium oxydisuccinate, tetraammonium oxydisuccinate, tetra(methylammonium) oxydisuccinate, tetra-(tetramethylammonium) oxydisuccinate, the normal monoethanolamine salt of oxydisuccinic acid, the normal triethanolamine salt of oxydisuccinic acid, the normal monoisopropanolamine salt of oxydisuccinic acid, the normal diisopropanolamine salt of oxydisuccinic acid, monosodium tripotassium oxydisuccinate, disodium dipotassium oxydisuccinate, trisodium monopotassium oxydisuccinate, the normal morpholine salt of oxydisuccinic acid, trisodium carboxymethyloxysuccinate, tripotassium carboxymethyloxysuccinate, trilithium carboxymethyloxysuccinate, triammonium carboxymethyloxysuccinate, the normal monoethanolamine salt of carboxymethyloxysuccinic acid, the normal diethan olamine salt of carboxymethyloxysuccinic acid, the normal triethanolamine salt of carboxymethyloxysuccinic acid, the normal tetramethylammonium salt of carboxymethyloxysuccinic acid, tri-(ethylammonium) carboxymethyloxysuccinate, the normal monoisopropanolamine salt of carboxymethyloxysuccinic acid, the normal diisopropanolamine salt of carboxymethyloxysuccinic acid, monosodium dipotassium carboxymethyloxysuccinate, disodium monopotassium carboxymethyloxysuccinate, the normal morpholine salt of carboxymethyloxysuccinic acid, and the like. Of course, it is to be understood that the compounds of the present invention which are shown structurally are available in both the anhydrous and hydrated forms.

The weight ratio of oxydisuccinate or carboxyme thyloxysuccinate builders to detergent compound when used in laundering and hand dishwashing compositions, ranges generally from about 1:20 to about 20:1. When the novel builders are used in mechanical dishwashing compositions, the ratio of builder to detergent compound is from about 10:1 to about 50:1.

The oxydisuccinate and carboxymethyloxysuccinate builders can be used either as the sole builder or where desired can be used in conjunction with other wellknown builders, examples of which include tetrasodium and tetrapotassium pyrophosphate, pentasodium and pentapotassium tripolyphosphate, trisodium and tripotassium nitrilotriacetate, polyacrylates, starch or cellulose derived polycarboxylates, and the like. Other materials which may be present in the detergent compositions of the invention are those conventionally present therein. Typical examples thereof include the well known soil suspending agents, hydrotropes, corrosion inhibitors, dyes, perfumes, fillers, optical brighteners, enzymes, suds boosters, suds depressants, germicides, anti-tarnishing agents, cationic detergents, softeners, chlorine releasing agents, buffers and the like. The balance of the detergent compositions is water.

The detergent compositions of the present invention may be in any of the usual physical forms for such compositions, such as powders, beads, flakes, bars, tablets, noodles, liquids, pastes and the like. The detergent compositions are prepared and utilized in the conventional manner. When using the detergent compositions of the invention to wash clothes, the wash solutions should have a pH from about 7 to about 12, preferably from about 9 to about 11. Therefore, the presence of a buffer in the detergent composition is usually desirable. Examples of such buffers are sodium silicate, carbonate or bicarbonate.

When the pH value of the wash solution is below about 8.6 some of the salts of the oxydisuccinic acid and carboxymethyloxysuccinic acid will be present in the acid salt form and some in the normal salt form.

An important advantage of the carboxymethyloxysuccinate in its excellent biodegradability characteristics as measured by both standard BOD tests (Biochemical oxygen demand for 5 days) and a modified Soap and Detergent Associations Semicontinuous Activated Sludge Test.

The normal oxydisuccinate builder salts can be prepared in the conventional manner. Thus, the tetrasodium oxydisuccinate may be prepared as follows: An aqueous solution containing 5 grams of oxydisuccinic acid (2,2'-oxydisuccinic acid) in 35 ml of distilled water is titrated to a pH of 8.6 with a 2 N sodium hydroxide solution. The aqueous solvent is removed under reduced pressure and the residue is tetrasodium oxydisuccinate (tetrasodium 2,2'-oxydisuccinate).

' Similarly using'carboxymethyloxysuccinic acid and the required amount of sodium hydroxide, the trisodium carboxymethyloxysuccinate can be prepared.

Employing a procedure similar to that given above, the corresponding normal alkali metal, ammonium and substituted ammonium salts of oxydisuccinic acid and carboxymethyloxysuccinic acid can be prepared by using a stoichiometric quantity of the appropriate alkaline reactant. The normal mixed salts of oxydisuccinic acid and carboxymethyloxysuccinic acid can be prepared by neutralizing oxydisuccinic acid or carboxymethyloxysuccinic acid respectively with the requisite proportional amounts of basic compounds containing the desired cations.

A preferred method for preparing the carboxymethyloxysuccinate is to react a mixed alkaline earth metal salt such as the calcium salt of maleic acid and glycolic acid in an aqueous alkaline medium. The pH of the medium should be adjusted with an alkaline earth metal reagent such as calcium hydroxide, strontium hydroxide or barium hydroxide.

It has been found that when the reaction is carried out at a pH range of 10.5 to 12.5 as measured initially at room temperature (about 25C) yields of about 80-95% carboxymethyloxysuccinate are obtained in a few hours or less. When the reaction is carried out at a preferred pH of about 1 1.3 to 12.0 as measured initially at room temperature which corresponds to about 9.9 to 10.3 at 100C, yields of 90% or better are obtained in less than 2 hours.

It has also been found that when using a relatively insoluble alkaline earth metal hydroxide such as magnesium hydroxide, the initial pH at room temperature of the reaction mixture even with an excess amount of the hydroxide is only about 8 to 9. However, by heating the reaction mixture at reflux temperatures or heating at superatmospheric pressure, satisfactory yields of the product can be obtained.

The mole ratio of glycolic acid to maleic acid used in the reaction is from about 1:1 to about 2:1 and preferably from 1.05:1 to about 1.2:1. The temperature at which the reaction may be carried out is normal reflux temperature (100102C) or below reflux temperature say, 60C. However, if the reaction is carried out at temperatures above reflux temperature 102200C, the rate of reaction is increased so that at certain elevated temperatures the reaction may be completed within a matter of minutes.

An interesting intermediate product formed during the reaction of the preferred process is the calcium chelate salt of carboxymethyloxysuccinate corresponding to the following empirical formula: C 1-1 O Ca The compound while represented in the anhydrous form is generally obtained in the hydrated form.

This calcium chelate salt corresponds to the calcium salt derived from two moles of the monocalcium chelate of carboxymethyloxysuccinate. The calcium chelate salt and the monocalcium chelate have utility as an animal feed, plant nutrient in any other area requiring calcium. Of course, other alkaline earth metal salts and other polyvalent salts such as zinc, iron, manganese, cobalt and the like could also be formed and used for the same or similar purposes.

While the calcium chelate salt can be isolated directly from the reaction because of its low solubility, the monocalcium chelate, which is highly soluble, must be obtained by either partially decalcifying the calcium chelate salt, e.g., ion exchange resin or, for example, by total decalciflcation followed by neutralization with one mole of calcium hydroxide and one mole of sodium hydroxide per one mole of carboxymethyloxysuccinic acid. For purposes of convenience, hereinafter the alkaline earth metal or polyvalent metal chelate salts and monoalkaline earth metal or polyvalent chelates of carboxymethyloxysuccinate will be referred to as simply salts of carboxymethyloxysuccinic acid.

While the alkali metal, ammonium and substituted ammonium salts of carboxymethyloxysuccinic acid are very effective builders, they are also effective as boiler scale removers, degreasers, grease cutters and rust and stain removers.

When the oxydisuccinic acid has been prepared in accordance with Example 1 of US. Pat. No. 3,128,287 issued to Chas. Pfizer and Company, Inc., it has been found that a mixture of two diastereoisomeric forms of oxydisuccinic acid will be obtained. The less soluble form has been designated as the d,l-racemate. The more soluble diastereoisomer has been designated as the meso form and is found in the aqueous filtrate after decomposition of the calcium salts with sulfuric acid and removal of the less soluble d,l-racemate. Accordingly, mixtures of meso and d,l-oxydisuccinic acid can be prepared as well as purified d,l-oxydisuccinic acid and a purified meso-oxydisuccinic acid. Thus these materials may be prepared as follows:

Maleic anhydride, 19.6 g (0.2 mole), is dissolved in 200 ml water and heated to C for 5 minutes. Calcium hydroxide, 16.0 g (0.22 mole), is then added and the mixture stirred and refluxed for four days. The insoluble calcium salts are filtered and dried. The dried product, 22 g, is slurried in water and passed through an Amberlite lR-12O cation exchange column to remove the calcium ions. The eluate is then evaporated to dryness to yield 14.5 g of crude oxydisuccinic acid. A. Mesa/d,l-Oxydisuccinic Acids 11 g of crude oxydisuccinic acid obtained from the above example is digested with 10 ml of boiling acetone and filtered. The acetone extraction is repeated five more times to give a 60/40 mixture of meso/d,loxydisuccinic acid based on NMR analysis.

B. d,l-Oxydisuccinic Acid Oxydisuccinic acid prepared by the Pfizer procedure was purified by first recrystallizing twice from a minimum amount of water. The recrystallized product, 20 g, was then dissolved in 600 ml boiling water and flushed through an Amberlite IR-120 cation exchange column to remove residual calcium cations. The eluate was then flash evaporated in vacuo to dryness. The residue was slurried with 100 ml of acetone, filtered and further washed twice with ml portions of acetone. After vacuum drying, 18.2 g of purified d,1- oxydisuccinic acid was obtained.

Examples of the detergent compositions of the invention are set forth below as illustrative but not limited to such compositions.

EXAMPLES 1-4 The detergent formulations set forth in Table I below (and in Tables Il-IX hereinafter) are prepared by blending together the recited components and are then tested for detergency or cleansing ability in the Terg-O- Tometer Test wherein the washing conditions are as follows (unless otherwise indicated): 65% Dacron-35% cotton VCD (vacuum cleaner dust) cloth; 120F; 180 ppm water (2/1 Ca /Mg 0.15% concentration of the total formulation in the washing solution; pH 9.5. (The pH of the washing solutions given herein was adjusted, where necessary, by the addition of caustic (NaOH) or sulfuric acid thereto).

The average detergency units (DU) of the formulations is the final reflectance of the washed cloth minus the initial reflectance of the soiled cloth (the average of two runs), the reflectance being measured with a Gardner Automatic Color Difference Meter, Model AC-3.

The following abbreviations have been used in the tables and examples: LAS is an anionic surfactant which is sodium linear secondary alkyl (C -C benzene sulfonate; Neodol 45-1 1 is a nonionic surfactant which is an adduct of a modified Oxo type C -C alcohol with an average of 11 moles of ethylene oxide; C C HAMT is an ampholytic surfactant which is sodium hydroxyalkyl (C -C N-methyltaurate; sulfobetaine DCH is a zwitterionic surfactant which is cocodimethylsulfopropyl betaine; NaODS is tetrasodium oxydisuccinate; STPP is pentasodium tripolyphosphate; TKPP is tetrapotassium pyrophosphate; NTA is trisodium nitrilotriacetate; RU silicate is a sodium silicate having a SiO Na O ratio of 2.4 l; DU is detergency units; and bal is balance.

The detergent (LAS) used in Examples l-4 is representative of the water-soluble organic anionic detergent compounds. Comparative Example lwhich contained only the organic anionic detergent compound, had low detergency of only 3.2 units. Comparative Example 2, which contained only tetrasodium oxydisuccinate, also had low detergency of only 2.3 units. Comparative Example 3, which contained the organic ani- 'onic detergent compound and pentasodium tripolyphosphate as a builder, had higher detergency of 22.5 units.

The remaining Example 4 is representative of the detergent composition of the invention. Example 4 contained the organic anionic detergent compound and tetrasodium oxydiscuccinate as a builder. This composition had a high detergency of 19.5 units, which value compares favorably with that for comparative Example 3 which contained the organic anionic detergent compound and phosphate builder. Thus, the detergent composition of Example 4 has high detergency properties amounting to 87% of the standard detergent form ulation of comparative Example 3 (19.5/22.5 X 100 87%).

EXAMPLES 5-8 TABLE 11 Percent by Weight Example No. 5 6 7 8 Neodol 45-11 l0 l0 l0 NaODS 50 50 STPP 50 Water bal bal bal bal Average Detergency 16.6 14.1 26.5 26.1 Units (DU) Comparative Example 5 in Table 11 above contained only the representative nonionic detergent compound and it had a detergency of only 16.6 units. Comparative Example 6, which contained only tetrasodium oxydisuccinate, had a detergency of only 14.1 units. Comparative Example 7 contained pentasodium tripolyphosphate as a builder in addition to the nonionic detergent compound. This formulation had higher detergency of 26.5 units.

Example 8, which is representative of the detergent compositions of the invention, contained in addition to the nonionic detergent compound, tetrasodium oxydisuccinate as the builder. This formulation had increased detergency of 26.1 units showing again that the tetrasodium oxydisuccinate functions quite satisfactorily as a builder and it is comparable in regard thereto to the phosphate builder. Thus, the formulation of Example 8 has excellent detergency properties amounting to 99% of the standard detergent formulation of comparative Example 7 (26.1/26.5 X 100 99%).

EXAMPLES 9-12 Comparative Example 9 in Table 111 above contained only the representative ampholytic detergent compound and it had a detergency of only 15.1 units. Comparative Example 10, which contained only tetrasodium oxydisuccinate, had a detergency of only 14.9 units. Comparative Example 11, which contained the ampholytic detergent compound and pentasodium tripolyphosphate as a builder, had a higher detergency of 26.9 units.

Example 12, which is a composition of the invention, contained the ampholytic detergent compound and tetrasodium oxydisuccinate as the builder. It is seen that the formulation of Example 12 has excellent detergency properties amounting to 96% of the standard detergent formulation of comparative Example 11 (25.9/26.9 X 100 96%). Thus, Example 12 further establishes that the tetrasodium oxydisuccinate functions as a detergency builder and it is comparable in that regard to the phosphate builders.

EXAMPLES 13-16 Examples 13-16 given in Table IV below contained a representative water-soluble organic zwitterionic de tergent compound identified above. These compositions were prepared and tested in the same manner as set forth in Examples 8.

Comparative Example 13 in Table IV above, which contained only the representative zwitterionic detergent compound, had a detergency of only 13.5 units. Comparative Example 14 contained only tetrasodium oxydisuccinate and had a detergency of only 13.0 units. Comparative Example 15, which contained the zwitterionic detergent compound and pentasodium tripolyphosphate as a builder, had an increased detergency of 26.4 units.

Example 16, which is a representative composition of the invention, contained the zwitterionic detergent compound and tetrasodium oxydisuccinate as a builder. This formulation had a high detergency of 25.6 units. Thus, once again, the formulation of Example 16 of the invention has excellent detergency properties amounting to 97% of that of the standard detergent formulation of comparative Example (25.6/26.4 X 100 EXAMPLES l720 The formulations of Examples 17-20 in Table V below differ from the preceding Examples 1-16 in that they further contain sodium silicate as a buffer. These compositions were prepared and tested as set forth in Examples 1-4 except the hardness of the wash water was at three varying concentrations, namely 50 ppm, 180 ppm and 360 ppm; the concentration of the total formulation in the washing solution was 0.20%; and the pH was 10.0.

In Table V above, Examples 17 and 18 are comparative formulations for Examples 19 and 20 respectively of the invention. It will be noted from the data therein that the zwitterionic detergent formulation containing tetrasodium oxydisuccinate (Example 19) and the nonionic detergent formulation containing tetrasodium oxydisuccinate (Example 20) maintained high detergency properties over the wide hardness range tested relative to their comparative formulations (Examples 17 and 18 respectively). Thus, Example 19 of the invention had excellent detergency properties amounting to 93% at 50 ppm, 88% at 180 ppm and at 360 ppm of that of the standard comparative detergent formulation of Example 17, while Example 20 of the invention also had excellent detergency properties amounting to at 50 ppm, 87% at ppm, and 88% at 360 ppm of that of the standard comparative detergent formulation of Example 18.

EXAMPLES 21-23 These three examples illustrate the effectiveness of tetrasodium oxydisuccinate as a detergency builder when used in combination with either an inorganic builder (STPP) or an organic builder (NTA). These compositions were prepared and tested in the same manner as set forth for Examples 17-20 except they were tested at 180 ppm hardness only.

From the data set forth above in Table VI, it will be noted that detergent compositions (Examples 22 and 23) containing tetrasodium oxydisuccinate in combination with an inorganic builder (pentasodium tripolyphosphate) or in combination with an organic builder (trisodium nitrilotriacetate) have excellent detergency properties amounting to 100% and 104% of that of the standard detergent formulation of comparative Example 21.

EXAMPLES 24-27 These four examples demonstrate the effectiveness of the detergent compositions of the invention in the cleansing of soil cloths other than the 65% Dacron-35% cotton VCD soil cloth used in the preceding Examples 1-23. Thus, in Examples 24-27 two different further soil test cloths were used, namely, cotton VCD (vacuum cleaner dust) cloth and FDS (Foster D. Snell) soil test cloth. The compositions were prepared and tested as set forth in Examples 2l23 except for the change in the soil test cloths.

In Table VII above, Examples 24 and 25 are comparative formulations for Examples 26 and 27 respectively of the invention. In comparing the data for Example 26 with that for Example 24, it will be noted that the formulation of the invention of Example 26 has excellent detergency on both of the additional soil cloths amounting to 95% (cotton VCD) and 99% (FDS) of the comparative standard detergent formulation of Example 24. The formulation of the invention of Example 27 when compared with comparative standard detergent formulation 25 also shows excellent detergency properties on cotton VCD cloth amounting to 94% of that of the standard detergent formulation of comparative Example 25. On the FDS cloth, however, the detergent formulation of the invention of Example 27 shows a surprisingly high margin of superiority in detergency properties amounting to 123% of that of the standard comparative detergent formulation of Example 25.

EXAMPLES 28-30 TABLE VIII vExample No.

Percent by Weight Neodol45-1l 1O 10 NaODS 12.5 TKPP 25 12.5

STPP 25 Water bal bal bal TABLE VIII-Continued Percent by Weight Example No. 28 29 30 Average Detergency Units (DU) From the data presented in Table VIII above, it will be seen that if one-half of the 'tetrapotassium pyrophosphate (TKPP) is replaced by tetrasodium oxydisuccinate (NaODS) (per Example 30), the detergency still amounts to 86% of that of the all TKPP formulation (comparative Example 28). In comparison to the pentasodium tripolyphosphate (STPP) comparative formulation of Example 29, however, the tetrasodium oxydisuccinate tetrapotassium pyrophosphate combination of Example 30 is superior with detergency amounting to 109% of that of the formulation of Example 29 (l5.3/l7.7 X 100= 86%and15.3/14.0 X 100 109%).

EXAMPLES 31-33 Examples 31-33 in Table IX below are illustrative of the utilization of tetrasodium oxydisuccinate in combi nation with an organic builder in detergent compositions and hence these examples constitute an extension of Examples 21-23 in Table VI and Examples 28-30 in Table VIII. These three formulations were prepared and tested in the same manner as set forth for Examples 2 1-23.

TABLE IX Percent by Weight From the data set forth in Table IX above, it is seen that a nonionic detergent formulation containing trisodium nitrilotriacetate as the organic builder (comparative Example 31) has excellent detergency amounting to 103% of that of the standard comparative detergent formulation of Example 32 (25.3/24.5 X 100 =103%). Replacement of U2 of the trisodium nitrilotriacetate by tetrasodium oxydisuccinate (Example 33 of the invention) lowers the detergency only slightly to 98% of that of the standard comparative detergent formulation of Example 32 (24.1/24.5 X 100 98%).

Results similar to those presented hereinabove are achieved when the normal oxydisuccinate salt is other than tetrasodium oxydisuccinate, such as the other normal oxydisuccinate salts set forth hereinabove, and when the detergent compositions contain further conventional additives.

Also as can be seen from the data of Examples 34-37, the stereoisomers of oxydisuccinate salts such as the meso form have good detergent building properties.

The effectiveness of the carboxymethyloxysuccinate salts as detergent builders is exemplified in Examples 38-55 and -73.

More specifically, Examples 38-47 show the use of trisodium carboxymethyloxysuccinate as a detergent builder with various surfactants. Example 48 describes the use of trisodium carboxymethyloxysuccinate in a machine dishwashing composition. Examples 49-51 illustrate the enhancement of the detergent building properties of trisodium carboxymethyloxysuccinate in the presence of added sodium sulfate. Examples 70-73 show the enhancement of detergent building properties of carboxymethyloxysuccinate by use of higher levels of surfactant.

In all cases except for Example 48 the detergency tests were carried out as set forth in Examples 1-4 and as modified in the description of the washing conditions stated at the beginning of the examples. In the case of Example 48, the detergency properties were established by washing artificially soiled glasses and dishes in a standard home dishwashing machine and comparing the results with those obtained with a standard sodium tripolyphosphate-built formulation. The artificial 2O soil is a mixture of milk, vegetable residues, lipstick, gravy, starch, eggs and lard.

Examples 52-69 show the preferred method for the preparation of carboxymethyloxysuccinic acid and the salts thereof. Tetrasodium salts of Meso/d,1 and d,l-

Oxydisuccinic Acids As Detergent Builders for LAS EXAMPLES 34-37 Washing Conditions: Terg-O-Tometer Detergency; Dacron/Cotton VCD cloth; 120F; Ca /Mg 0.2% Concentration of Total Formulation; pH 10.0

Formulation 37 180 ppm (2:1

EXAMPLE 48 A machine dishwashing composition is prepared with the following materials:

Trisodium salt of carboxymethyloxy- 43.0% succinic acid Chlorinated trisodium phosphate 21.0% N Silicate solids (3.22 SiO /Na O ratio) 14.0% RU Silicate solids 12.0% Pluronic L62 (A nonionic surfactant 2..5% sold by Wyandotte Chemical Corporation which is an ethylene oxide condensate of a polyoxypropylcne glycol) Sodium sulfate 4.7% Water 2.8%

The above formula has acceptable dishwashing properties which are similar to the same formula containing sodium tripolyphosphate in place of the trisodium carboxymethyloxysuccinate.

EXAMPLES 49-51 Detergency Building Properties of Trisodium Carboxymethyloxysuccinate with Sodium Sulfate Washing Conditions: Terg-O-tometer; Dacron/Cotton VCD Cloth; 120F; 180 ppm (2:1 Ca /Mg water; 0.1% formulation concentration; pH 10.0

Components Formulation LAS 18 18 18 Trisodium Carboxymethyl- 40 oxysuccinate STPP 40 Sodium sulfate 23 23 RU-Silicate solids 10 10 10 Water bal bal bal Detergency (DU's): 22.7 21.9 22.8 7: Efficiency 100 96 (49 vs. 51 and 50 vs. 51):

Trisodium Carboxymethyloxysuccinate As A Detergent Builder Examples 38-47 Washing Conditions:

Tero-O-Tometer; Dacron/Cotton VCD Cloth; 120F; 180 ppm (2:1 Ca /Mg water; 0.20%

Concentration of Total Formulation for Examples 38 and 39; 0.25% Concentration for Examples 40 to 47;

pH 10.0 Component Formulation (7%) Trisodium salt of carboxymethyl- 50 5O 50 50 50 oxysuccinic acid STPP 50 5O 50 50 50 RU Silicate solids 10 10 10 10 10 1O 10 10 10 10 LAS 18 18 Neodol 45-11 10 1O C -C HAMT 18 18 Sulfobetaine DCH 18 18 Sodium C, C a-olefin sulfonate 18 18 Water bal bal bal bal bal bal bal bal bal bal Average Detergency (DUs) 23.0 24.3 21.6 24.1 19.7 24.1 23.5 24.3 22.6 24.9 Efficiency vs. Control Formulation: 95 82 97 91 i.e., 38 vs. 39; 40 vs. 41; 42 vs. 43; 44 vs. 45 and 46 vs. 47

EXAMPLES 52-53 Preferred Preparation of Trisodium Carboxymethyloxysuccinate maleic anhydride (0.2 mole; 19.6 g) is dissolved in water (100 ml) at room temperature and stirred for 10-15 minutes to convert it to the acid. Glycolic acid (0.24 mole; 18.3 g) is then added and dissolved with stirring. Calcium hydroxide, (ca0.36 mole; 27 g), sufficient to attain a pH of 11.4 as measured initially at 25C is next added while stirring the reaction mixture vigorously. The mixture is heated to reflux and maintained at reflux for two hours while stirring vigorously. After cooling to 60C, finely ground sodium carbonate (0.4 mole; 42.4 g) is added and stirring continued for 15 minutes at 60C. The mixture is then cooled to room temperature and the suspended CaCO filtered off and washed with water. The filtrate (including the washings) contains the product, trisodium carboxymethyloxysuccinate, in yields of about 95% as determined by NMR analysis.

The NMR analysis, which can be run before or after treatment with the sodium carbonate, involves taking a 25 ml sample of the reaction mixture and treating it with a cation exchange resin. After filtering and washing the resin with water, the combined filtrate and washings are evaporated to a residue in vacuo. An NMR analysis of the residue in D is then performed. The percent conversion of maleic anhydride to carboxymethyloxysuccinate equals 100 X [ratio of the area of the chemical shift for carboxymethloxysuccinic acid at 2.6-3.3 8 (2H) to the sum of the areas for the chemical shifts for unreacted maleic acid at approximately 6.3 6 (2H), fumaric acid (which may form during reaction) at approximately 6.8 8 (2H) and carboxymethyloxysuccinic acid at 2.6-3.3 8 (2H)]:

The above procedure of Example 52 is repeated except the mixture is refluxed for 30 minutes as opposed to 2 hours and the pH of the solution obtained after filtering off the CaCO is adjusted to 8.6 with 10% sulfuric acid. Yields of about 93% are obtained.

EXAMPLE 54 The reaction mixture from Example 52 is cooled and before treatment with sodium carbonate, the intermediate calcium chelate salt is isolated by filtration Ca calculated for C H O Ca 'H O, 22.5%; found, 22.9%). The product is then decalcified by treatment of an aqueous slurry of the product with a cationexchange resin followed by filtration and evaporation of the filtrate. The residue of carboxymethyloxysuccinic acid solidifies on cooling to a crystalline mass, m.p. l l21 13C. The acid is then converted into a salt by partial or complete neutralization with sodium hydroxide to form mono-, dior trisodium carboxymethyloxysuccinate.

EXAMPLES 55-59 In place of the calcium hydroxide of Example 52, the divalent metal hydroxides Mg(OH) Sr(OH) Ba- (OH) and Zn(OH) are used.

Using Mg(OH) in the reaction of Example 52 with .200 ml of water in place of 100 ml of water and at an initial pH of 9 (measured at room temperature) gives a 79% conversion of maleic anhydride into product after 17 hours refluxing at 100C. Similarly with Sr (OH) at initial pH of 1 (measured at room temperature), the conversion is 88% in four hours at C. With Ba(OH) at initial pH of 10-11, the conversion is 54% after 10 hours at 100C. With Zn(OH) and at an initial pH of 8, a 47% conversion is obtained after 9 hours at 100C. With Ca(OH) at initial pH of 11, the conversion is 91.5% in less than 15 minutes at C. The speed of the reaction with Ca(OH) makes it feasible for the process to be run continuously.

EXAMPLES 60-65 The procedure of Example 52 is repeated except that 200 ml of water is used and the amount of calcium hydroxide used is sufficient to obtain the following pHs as measured initially at room temperature.

% Conversion of Maleic Anhydride to Trisodium Carhoxymethyloxysuccinute ExampH after Two Hours Refluxing ple EXAMPLE 66 The procedure of Example 52 is repeated except that 200 ml of water is used and 27.5 g of zinc oxide (.338 moles) is used in place ob 27.0 g of calcium hydroxide to adjust the pH to about 8.0. The percent conversion of maleic anhydride to trisodium carboxymethyloxysuccinate after two hours refluxing is 41% as determined by NMR analysis.

EXAMPLES 67-68 EXAMPLE 69 The procedure of Example 52 is repeated except the pH is adjusted to 12.0 and the reaction mixture is refluxed for 15 minutes. The conversion of maleic acid to carboxymethyloxysuccinate is 90% based on NMR analysis.

At high pH and continued refluxing, the carboxymethyloxysuccinate product formed may undergo a retro- Michael reaction giving rise to the fumarate salt.

Referring to Examples 70-73, it has been determined that by increasing the level of the surfactants used in the detergent formulations and particularly the anionic and zwitterionic actives, the detergencies of the formulations are enhanced. It has also been found that LAS and alpha-olefin sulfonate salts are very effective for this purpose.

Examples 70-73 clearly demonstrate that when the levels of LAS are increased, the detergency of the formulation is enhanced significantly when compared to a standard LAS/tripolyphosphate formulation. When using other actives, similar effects are observed.

EXAMPLES 70-73 Trisodium Carboxymethyloxysuccinate As A Detergent Builder With Various Levels of An Anionic Surfactant Washing Conditions: Terg-O-Tometer; Dacron/Cotton VCD cloth; 120F; 180 ppm (2:1 Ca /Mg water; 0.2% concentration of total formulation; pH 10.0

formulation:

EXAMPLES 7475 Preparation of Trisodium Carboxymethyloxysuccinate Tetraand Pentahydrates The trisodium carboxymethyloxysuccinate obtained from Example 52 is dried in a vacuum oven over phos phorus pentoxide. The dried trisodium carboxymethyloxysuccinate is then dissolved in a hot 80% (by volume) alcohol-water solution. The solution is then allowed to cool to crystallize trisodium carboxymethyloxysuccinate pentahydrate (25.8% water). This material is found to be non-hygroscopic over a wide range of humidity conditions.

The carboxymethyloxysuccinate of Example 52 is dried under vacuum over phosphorous pentoxide. The material is then exposed for about 2 days to humidity conditions of 40 to 70% relative humidity at room temperature to form the trisodium carboxymethyloxysuccinate tetrahydrate. This material is found to be stable over a wide range of humidity conditions.

It is intended to cover all changes and modifications of the preferred embodiments of the invention, herein chosen for the purpose of illustration, which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

l. Carboxymethyloxysuccinic acid and the salts thereof having the formula:

MOOC- H H COOM wherein M is selected from the group consisting of hydrogen, alkali metal, ammonium, morpholinium, alkylammonium, mono-, di-, or trialkanolammonium cations.

2. A compound selected from the group consisting of zinc, and alkaline earth metal salts of carboxymethyloxysuccinic acid.

3. The compound of claim 2 wherein the carboxymethyloxysuccinate salt is the calcium salt of carboxymethyloxysuccinic acid having the empirical formula 6 5 7 L5- 4. Sodium monocalcium salt of carboxymethyloxysuccinic acid.

5. A process for the preparation of the salts of carboxymethyloxysuccinic acid comprising the steps of:

i. forming a mixed salt of glycolic acid and maleic acid by reacting said acids in an aqueous medium with a compound selected from the group consisting of zinc hydroxide, zinc oxide, alkaline earth metal hydroxides, alkaline earth metal oxides and mixtures thereof at a pH of about 8.0 to about 12.5 as measured at about 25C,

. heating said mixed salt to form a reaction mixture containing the zinc or alkaline earth metal salts of carboxymethyloxysuccinic acid, and

iii. treating said reaction mixture in order to substitute alkali metal, ammonium morpholinium, alkylammonium; mono-, di-, or trialkanolammonium cations for the zinc or alkaline earth metal cations to form the alkali metal, ammonium morpholinium, alkylammonium, mono-, di-, or trialkanolammonium salts of carboxymethyloxysuccinic acid.

6. The process of claim 5 wherein the alkaline earth metal salt of carboxymethyloxysuccinic acid is treated with an ion exchange resin.

7. The process of claim 5 wherein the mixed salts are heated to reflux temperatures for at least 15 minutes.

8. The process of claim 5 wherein heating of the mixed salts is carried out at temperatures from about 102 to about 200C.

9. The carboxymethyloxysuccinate salts of claim 1 wherein said salts are substantially non-hydrated.

l0. Trisodium carboxymethyloxysuccinate tetrahydrate.

l1. Trisodium carboxymethyloxysuccinate pentahy- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 914 297 Dated October 21, 1975 Inventor(s) Vincent Lamberti, Mark D. Konort, and Ira Weil It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, Line 26, change "substituted" to substitutes--.

Column 3, Line 8, change "in" to -is.

Column 8, Table V, Line 19, change "Ru" to RU.

. Column 13, Line 5, change "maleic" to -Maleic..

Column 16, Line 34, after ammonium put a (comma) Column 16, Line 37, after ammonium insert a (comma) Signed and Scaled this Twenty-sixth Day of October 1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner'ojParents and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3 914 297 Dated October 21, 1975 Inventor(s) Vincent Lamberti, Mark D. Konort, and Ira Weil It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, Line 26, change "substituted" to -substitutes.

Column 3, Line 8, change "in" to is-.

Column 8, Table V, Line 19, change "Ru" to RU.

. Column 13, Line 5, change "maleic" to --Maleic.

Column 16, Line 34, after ammonium put a (comma) Column 16, Line 37, after ammonium insert a (comma) Signed and Scaled this Twenty-sixth Day of October 1976 [SEAL] AIIESI.

RUTH C. MASON C. MARSHALL DANN 8 ff Commissioner ofPaIents and Trademarks 

1. CARBOXYMETHYLOXYSUCCINIC ACID AND THE SALTS THEREOF HAVING THE FORMULA:
 2. A compound selected from the group consisting of zinc, and alkaline earth metal salts of carboxymethyloxysuccinic acid.
 3. The compound of claim 2 wherein the carboxymethyloxysuccinate salt is the calcium salt of carboxymethyloxysuccinic acid having the empirical formula C6H5O7Ca1.5.
 4. Sodium monocalcium salt of carboxymethyloxysuccinic acid.
 5. A process for the preparation of the salts of carboxymethyloxysuccinic acid comprising the steps of: i. forming a mixed salt of glycolic acid and maleic acid by reacting said acids in an aqueous medium with a compound selected from the group consisting of zinc hydroxide, zinc oxide, alkaline earth metal hydroxides, alkaline earth metal oxides and mixtures thereof at a pH of about 8.0 to about 12.5 as measured at about 25*C, ii. heating said mixed salt to form a reaction mixture containing the zinc or alkaline earth metal salts of carboxymethyloxysuccinic acid, and iii. treating said reaction mixture in order to substitute alkali metal, ammonium morpholinium, alkylammonium; mono-, di-, or trialkanolammonium cations for the zinc or alkaline earth metal cations to form the alkali metal, ammonium morpholinium, alkylammonium, mono-, di-, or trialkanolammonium salts of carboxymethyloxysuccinic acid.
 6. The process of claim 5 wherein the alkaline earth metal salt of carboxymethyloxysuccinic acid is treated with an ion exchange resin.
 7. The process of claim 5 wherein the mixed salts are heated to reflux temperatures for at least 15 minutes.
 8. The process of claim 5 wherein heating of the mixed salts is carried out at temperatures from about 102* to about 200*C.
 9. The carboxymethyloxysuccinate salts of claim 1 wherein said salts are substantially non-hydrated.
 10. Trisodium carboxymethyloxysuccinate tetrahydrate.
 11. Trisodium carboxymethyloxysuccinate pentahydrate. 